... certificate astm oil pipe 4 inch SpecificationOD 33mm - 406mm(1”~16”) with thickness of 3~30mmStandardGB/T8162,GB/T8163 and DIN/JIS/ASTM ... -C),20#(ASTM A106/53 Gr.B, A178-C,A210-A-1,A315-B,AISI1020),45#(AISI1045), 16mn(ASTM A210-C ... , machinery, traffic, aviation, oil development etc. seamless pipe for low and medium pressure boiler,high prssure boiler,ship-building ,petroleum cracking ...